LOCATION JUANA DIAZ PREstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, isohyperthermic, shallow Typic Haplustepts
TYPICAL PEDON: Juana Diaz clay loam - rangeland. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 6 inches; dark yellowish brown (10YR 3/4) 80 percent, dark brown (10YR 4/3) 20 percent, (0-15 cm) clay loam; moderate fine and medium granular structure; firm, slightly sticky, plastic; many fine roots; neutral; abrupt smooth boundary. (5 to 7 inches thick)
Bw--6 to 12 inches; dark yellowish brown (10YR 4/4) clay loam, weak medium and coarse subangular (15-30 cm) blocky structure; firm, slightly sticky, plastic; common fine roots; neutral; clear smooth boundary. (5 to 7 inches thick)
BC--12 to 18 inches; yellowish brown (10YR 5/6) silt loam; weak medium subangular blocky structure; (30-45 cm) friable, slightly sticky, slightly plastic; few fine roots; 15 percent by volume of saprolite; mildly alkaline; clear smooth boundary. (4 to 6 inches thick)
Cr--18 to 40 inches; consists of semi-consolidated sandstone that can be easily broken with the spade.
TYPE LOCATION: Caribe SCD, Puerto Rico; 80 feet south of kilometer marker 15.75 of Highway 14.
RANGE IN CHARACTERISTICS: Thickness of the solum and depth to the sandstone ranges from 14 to 20 inches. Reaction ranges from slightly acid to mildly alkaline. Rock fragments range from 0 to 35 percent.
The A horizon has hue of 10YR, value of 3 or 4, and chroma of 3 or 4. Texture is clay loam. Consistence is slightly sticky and plastic.
The Bw horizons hue of 10YR, value of 4 or 5 and chroma of 4 or 6. Texture is silt loam, clay loam or loam, and never exceed 35 percent in clay. Structure ranges from weak medium to weak fine subangular blocky. Consistence is sliightly sticky and plastic in the upper B horizons, and friable in the lower B horizons.
The BC horizon has similar color and texture as the Bw horizon. Saprolite ranges from 10 to 40 percent.
The Cr horizon is semi-consolidated sandstone.
COMPETING SERIES: These are the Callabo, Victory, and Vieques series in the same subgroup, and the Diamond, Pandura, Sabana, and Yunes series. The Callabo soils are finer textured. The Victory soils are thicker. The Vieques soils are coarser textured, and have coarse fragments. The Diamond soils have hard limestone within 20 inches and colors of soil are in redder hues. Pandura soils have a thinner, coarser textured solum. Sabana soils have hard volcanic rock within 20 inches and solum is more acid. Yunes soils have coarse fragments throughout the solum and the soil is more acid.
GEOGRAPHIC SETTING: The Juana Diaz soils occur on moderately to steeply sloping rounded hilltops and sideslopes with slope gradients from 20 to 40 percent. The soil formed in loamy residuum weathered from sandstone. The climate is semiarid. Average annual precipitation ranges from 25 to 40 inches. Mean annual temperature is 80 degrees F. The range in mean annual soil temperature is from 78 to 80 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: There are no associated soils.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: Most of the acreage is in rangeland or pasture.
DISTRIBUTION AND EXTENT: Semiarid sections of Puerto Rico. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina
SERIES ESTABLISHED: Puerto Rico; l936.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - zone from 0 to 6 inches (A horizon)
Cambic horizon - zone from 6 to 18 inches (Bw and BC horizons)
Paralithic contact - zone at 18 inches (Cr layer)
This series was formerly classified in Reddish Chestnut great soil group.